A player home must contain at least the following things:

• 1 2×2 area made of one of the allowed tilesets.

• A door with the tag “MAIN_DOOR” that will be used to leave the house.

• Choose a specific loading screen. (The default the loading screen is set to random, which is bad.)

You can then choose the area lightning and ambient music that you want, add placeables, sounds, more doors, waypoints, triggers, visual effects and more!

Each area can have up to 1500 objects and 250 of them can be dynamic, a dynamic object is either a non-static placeable, a door, a trigger or a visual effect. Sinfar Supporters limit is twice that amount (500 dynamic and 3000 static)

(You may not put in your own items or creatures, or any merchants or scripts beyond those supported on Sinfar's houses script list page.)

1. Find a location: Player houses are characterized by a sign with a title such as “House #5”, next to a door and the sign should say “For sale!” with the details on how the interior can be designed, for example:
   
   
   
2. Go the the realtor: There's one for most islands or you can cheat and use the one in the OOC which is for all islands:

The interior of you house can be built using the Neverwinter Nights Toolset.

You can start building with this module: V27 Starter Mod and Hak

1. Extract the module to your NWN\modules folder.
2. Extract the hak to your NWN\hak folder.

Create the first area:

1. Select one of the allowed tileset
2. Select a size within the allowed range (the format on the deed is: Width x Height)
3. Add a door and set the tag to “MAIN_DOOR”. This is the door that will be used to enter and leave the house, you don't have anything else to do, its transition will be setup automatically. It can have a custom appearance and the exterior door will be updated to have the same appearance.

Save the module, upload it and you should be able to enter your house in game!

Here's what the process looks like:

The housing system is made so that you can even make your own scripts for inside your house and they will have no effect outside of it when ran. This feature is although restricted to selected players and Sinfar Supporters.

Read more here: scripts